Dividing machine and the like



Ang. 15, 1939. 2,169,308

H. (JOHANN KONRAD) WAGNER. ET AL DIVIDING- MACHINE AND TB LIKE Filed oct. 2. 1937 Fig. 1

A tof-neg Patented Aug. 1,5, 1939 UNITED STATES PATENT OFFIC Hans (J ohann Konrad) Wagner and Hans- Joachim Sommer, Oberfranken, Germany Application october z, 1937, serial-No.

Germany October 6, 1936 10 Claims. (Cl. 33-19) The graduation marks on dial plates and the like are usually engraved by fixing the workpiece on a support which is rotatably mounted underneath the graving tools, the support being moved through a distance corresponding to the graduation of the scale and then stopped, whereupon the graving tools come into operation. At the end oi' the working stroke, the tools are raised out of contact with the workpiece which is again moved through one degree of the scale, after which the same working operation is repeated.

It has now transpired that, especially in the case of unequal graduations, for which a high degree of precision is required, the desired result cannot be directly achieved by purely mechanical means. Even slight wear or fouling of the spaclving devices of a mechanical control device cause differences in the movement of the workpiece, which lead to inaccuracies in graving the individual graduation marks.

According to this invention, the defects of the mechanical control devices are' remedied by controlling the movement of the workpiece by lightray scanning through a templet in positive connection with the arrangement which moves the workpiece. 'I'hrough the agency of a' photoelectric cell, the light ray iniiuences a relay or the like which controls the arrangement actuating the workpiece. To stop the movement for example, the arrangement may be such that, under the inuence of the ray, the relay disengages a clutch driving the spindle of the device supporting the work. In a similar manner, the ray may replace a clutch for controlling the switch of the motor driving said spindle. The reengagement of the clutch, or the switching on of the motor driving said spindle, may be effected, for example,'by means of a mechanical or electrical connection with the drive actuatingrthe work. Alternatively, a screen or a second templet, may be provided which also enables the motor to be switched on, or the clutch let in, by means of a light ray. Details of the special embodiment of the arrangement are set out in the following description.

Some typical embodiments of the subject of the invention are diagrammatically illustrated in the drawing as applied to a circle dividing machine.

Figure 1 is an arrangement Icontrolled byva templet, mounted on a support and scanned with a light ray.

Figure 2 is a similar arrangement, in which, however, a templet 0f lexible material passes over two rollers,

- gear 2.

Figure 3 shows the arrangement of a. motor switch controlled by a photo-electric cell.

Figure 4 shows an arrangement of the photoelectric cell, in which the resumption of movement is effected byl means of a second ray and 5 a screen.

According to Figure 1, the dial plates I to be graduated are mounted on rotatable supports, each of which is integrally formed with a worm .These worm gears are engaged by worms 10 3 provided on shaft 4. The shaft 4 is positively connected through a pair of spur gears 5, 6 with al second shaft I carrying a support 8 on which is arranged a templet 9 provided on an enlarged scale, if desired, with the graduation to be repro- 15 duced. Shaft I is provided with a threaded p0rtion coacting with a corresponding threaded portion of support 8 so that rotation of shaft 1 Will cause linear vdisplacement of the support and of templet 9 arrange (not shown) are provided to prevent rotation of support 8 with shaft 'I.

The shafts 4 and I are driven by a motor II through a clutch I0. Interposed between the motor II and the clutch I0 is a transmission gear 25 I 2, I3 serving to drive a shaft I4 which actuates the cutting tools I6 through the agency of cams I5.

Rotating the spindle 4 actuates both the workpieces I through worms 3 and worm gears 2 and 30 the'templet 9. 'I'he templet 9 through gears 5 and 6, threaded spindle 'I and support 8 is scanned by a light ray, emitted by the source of light I'I and reaching the photoelectric cell I8 after reflection on the templet 9. If, during the move- 35 ment of the templet 9, its reiiective capacity be modified, for example by a reflecting point I 9 reecting the ray on to the photoelectric cell I8, the light entering the cell I8 generates a current therein. The resulting current impulse acts, 40 through an amplifier, on a relay 20 which disengages the clutch I Il in known manner, for example by magnetic means. Since this breaks the connection between the shafts 4 and 'I with the motor I I, both the workpiece I and the templet 45 are stopped. The ratio of the gear I2, I3 is so determined that, in the event that the reflecting points I9 of the templet 9 are unevenly spaced, the shaft I4 describes a rotation corresponding to the widest spacingv on the graduation of the templet. If, as the result of the action of the ray on the photoelectric cell I8 and the consequent disengagement of the clutch, the workpiece I is now stationary, the cams I 5 actuate the graving tools I 6 after the motor shaft has described a 55 d thereon. In addition, means 20 by any convenient control shaft 4 finally re-engages corresponding number of revolutions.l Each of these tools engraves a graduation mark in the workpiece, and all of them are then raised out of contact with the workpieces in known manner, means. The rotating the clutch I9 through a control cam 2| and lever mechanism 22. After this clutch is re-engaged, the workpieces fl` and templet 9 continue to advance conjointly, until a'reecting point I9 again reects the ray coming from the source of' light I1, to the photoelectric cell I3. The above described working operation is then repeated.

The templet may also be provided with slots for the passage of the light. With such an arrangement, the source of light is located on one side of the templet, and the photoelectric control member on the other side. The templet may consist of any convenient material, for example of a metal strip provided with slits spaced in accordance with the graduation to be reproduced. It is also possible, by a suitable selection of the gear ratio of gears 5, 6 to produce very close set graduation marks on the workpiece with a more widely graduated templet. Similarly, by a suitable selection of gear ratio, the graduations produced on the workpiece could be more widely spaced than the spacing on the templet.

In place of metal, the templet, may be composed c'f some other suitable material. For example, a strip of film can be used, which is provided with suitably spaced translucent and opaque zones.

Figure 2 represents another typical embodimen of the subject of the invention. Instead of a single motor, separate motors II and 23. are provided for driving the workpiece spindle' and the shaft I4 actuating theA tools. The motor II drives the shaft 4 through a clutch I9 in the manner already described, said shaft in turn actuating a toothed drum 25 through cone-pinion gear 24. Over said drum runs a templet 9 of iiexible material, provided with the graduation marks to be reproduced and also with slots or holes engaged by the teeth of the drum 25, in order to keep it in the-correct position on the drum. As shown in this Figure 2, the templet 9 is scanned by the light ray emitted by the source of light I1, and transmits the light tric cell I8. In turn, the current generated in said cell I8 actuates the clutch I0, through a 'relay 20. As already described, the clutch is reengaged by the tool shaft I4 acting through a cam 2l and the lever mechanism 22. If desired, the lever mechanism 22 may also be connected with a switch, in both the embodiments shown in Figures l and 2, said switch serving to break the circuit when the clutch is in again. During the further rotation of the shaft I4, however,y the switch is turned over again, so that, when the light ray again acts on the photoelectric cell, the clutch can be again disengaged by electromag-l netic action.

According to Figure 3, the clutch can be replaced, in special cases, by an electric cut-out 2S for the motor II. In such event, the current from the photoelectric cell I8 acts,'through a relay 29 on said switch and thus shuts olf the supply of current to the motor II.

.In order to stop the motor II as soon as the current is shut olf, the motor shaft is fitted with a braking device 21. This is preferably actuated electrically, in such a manner that the brake blocks bear, under spring pressure, against a brake drum, or the like, when the current to the motor ray on to the photoelec is shut off. It has been found specially advisable to switch the brake current on, or off, shortly before the motor current is shut oif, in order to overcome the hysteresis phenomena of the brake magnet. The electromagnetic brake is released before or at the time, when the motor current is ,switched-in again.

In the embodiment shown in Figures 1 and 2, ,the tools are set in action again by a cam on the tool shaft. Such cam transmission can be replaced with advantage, by a light-scanning device. Diagrammatically represented in Figure 4 is an arrangement which, in contrast to the above described en bodiments interrupts the actuation of the tool spindle when an opaque zone of the templet 9 comes into position between the source of light II and the photoelectric cell I8.

The actuation of the clutch and of relay 20 is so arranged that the .clutch is engaged when ,the current is turned on, but disengages automatically, under the pressure of a spring, or like means, as soon as the current is shut olf. With this arrangement, the resumption of movement of the workplaces can be effected by means of the same photoelectric cell as is employed for stopping said movement. Connected with the tool shaft I4 is a screen 28, on one side of which is a second source of lightl 29, whilst, on the aperture side of the photoelectric cell I8 is arrangedga prism 39. If now a translucent zone 3l ofthe screen 28 arrives in position between the source of light 29 and the prism 30 of the photoelectric cell I8, the clutch of the tool spindle will be re-engaged. The joint movement of the tool and the templet 9 will then continue until an opaque rone of the templet 9 again comes into the path of the ray of light from the source I1. The ray is thus interrupted and the clutch is released, by spring action or the like, so that the tool and templet come to a stop. Re-engagement is eected, by means of the second source of light 29, at the instant the tool shaft I4 has turned far enough for a second translucent zone 3l of the screen 28 to be brought in front of the source of light 29.

The ray from the source of light 29 passes through slits 3l and encounters the prism, where it is refracted and led intov the interior of the photoelectric cell. Through the resulting curfrent impulse the workpiece shaft is re-engaged,

so that the templet already described.

As mentioned above, the ratio of the gear I2, I3 for actuatingthe tool shaft must be so selected that the working strokes of the tools II take place at time intervals which correspond to the maximum spacing of the slits I9 in the templet 9. Accordingly, in the case of unequal graduations, the tool shaft I4 idles for a certain time in the zones of finer graduation. To avoid such idling, the device can, if desired, be so arranged that the tool shaft I4 is controlled, in subordination to the workpiece shaft 4 or to the shaft 1 actuating the templet 9. To accomplish this result, the singleacting clutch I9 may bIe replaced by a doubleacting clutch, so that the drive of the shaft I4 is put into operation each time the shaft 4 is disconnected. Then, ln the ,mannerl already described, the control cam 2| re-engages the clutch Ill, to actuate the shafts 4 and 1, at the end of each working stroke of the tools' I6. two separate motors are employed for driving the shafts 4 and I4, a separate clutch can be arranged in the drive of the shaft I4, which clutch, in conjunction with the clutch 9 and workpiece advance as When I9 of the workpiece shaft F15 that is necessary is to produces the same eiect as that described for a double-acting clutch.

If graduations are to be inscribed on measuring rules or the like, instead of on dial plates, all replace rotatable supports 2 by longitudinally movable supports, which are driven by shaft 4.

What We claim isl. In an apparatus for providing graduation l piece.

l2. In an apparatus for providing graduation marks on workpieces in accordance with corresponding divisions of a templet, the combination comprising means for intermittently and simultaneously displacing a workpiece and a templet, said templet bearing visible marks thereon, marking means adapted to provide marks on said workpiece when actuated, means -for driving said displacing and said marking means, and photoelectric scanning -means actuable by the visible marks of said templet to operate said displacing and said marking lmeans in predetermined time relationship to cause graduation of said workpiece, said scanning means including a light ray directed onto the marks of said templet and a photoelectric cell and a relay.

3. In an apparatus for providing graduation marks on Workpieces in accordance with corresponding divisions of a templet, the combination comprising means for intermittently and simultaneouslydisplacing a workpiece and a templet bearing visible marks thereon, marking means adapted to provide marks on said workpiece when actuated, means for driving said displacing and said marking means in predetermined time relationship, means for projecting a ray of light onto 'the marks of said templet, a photoelectric cell iniiuenced by said ray modified by said marks, and means actuated by said photoelectric cell to render said driving means temporarily inoperative during graduation of -said workpiece by said marking means.

4. In an apparatus for providing graduation marks on workpieces in accordance with corresponding divisions of a templet, the combination comprising means for intermittently and simultaneously displacing a workpiece and a. tempiet bearing visible marks thereon, marking means adapted to provide marks on said workpiece when actuated, means for driving said displacing and said marking means in predetermined time relationship, means for projecting a ray of light onto the mark'sof said templet, a photoelectric cell inuenced by said raymodified by said marks, and a clutch actuated by said photoelectric cell to render said driving means temporarily inoperative during the time when said marking means are actuated whereby graduation marks are provided on said workpiece by said marking means.

5. In an apparatus Vfor marks on workpieces, ing means including a providing graduation the combination comprisrotatable displacing shaft for intermittently and simultaneously displacing a workpiece and a templet, said templet bearing visible marks thereon corresponding to the desired graduation, marking means including a tool shaft adapted to provide marks on 'said workpiece when actuated, a driving motor for said displacing shaft and for said tool shaft, photoelectric means actuable by said y visible marks in a predetermined position thereof adapted to interrupt the circuit of said displacing shaftmotor, and brake means automatically engaging said motor when its circuit is interrupted.

6. In an apparatus for providing graduation marks on workpieces, the combination comprising means including a workpiece spindle for intermittently displacing a workpiece and a templet, said templet bearing visible marks thereon corresponding to the graduations desired on the workpiece, `marking means including graving tools and a tool drive capable of providing marks on said workpiece when actuated, a driving motor for said spindle, a second driving motor for said tool drive, a clutch interposed between said spinl die and said rst driving motor, photoelectric means including a light ray and a photoelectric .cell and a relay actuable by said visible marks on said templet in predetermined positions thereof to disengage said clutch, and means actuated by said tool drive to cause reengagement of said clutch upon completion of the working stroke of the graving tools.

,7. In an apparatus for providing graduation marks on workpieces, the combination comprising means including a workpiece spindle for intermittently displacing a workpiece and a templet, said templet bearing visible marks thereon corresponding to the graduations desired on the workpiece and being displaced at a different rate than said workpiece, marking means including graving tools and a tool drive for marking said workpiece, a motor for driving said spindle and said tool drive, a clutch interposed between said motor and said spindle, photoelectric means including a photoelectric cell actuated by said visible marks on said templet in predetermined positions thereof to disengag'e said clutch, -and means actuated by said tool drive to cause reengagement vof said clutch upon completion of the working stroke of the graving tools.

8. In an apparatus for providing graduation vmarks on workpieces, the combination comprising means including a workpiece spindle for intermittently displacinga workpiece and a templet, said templet being constituted of a strip of solid material in which slits for the passage of light are spacedly provided in accordance with the graduation to be reproduced, marking means including graving tools and a tool drive for markingsaid workpiece, a motor for driving said spindie, a clutch interposed between said motor and said spindle, means for 'projecting a light ray onto the slits of said templet, photoelectric means actuated by said light ray in predetermined positions of said templet to disengage said clutch, and means actuated by said tool drive to cause reengagement of said clutch upon completion of the working stroke of the graving tools.

A 9. In an apparatus for providing graduation marks on workpieces, the combination comprising means including a. workpiece spindle for intermittently displacing a. workpiece and a. templet, said. templet being constituted of a strip of transparent material having translucent and opaque zones spacedly provided therein in accordance with the graduations to be reproduced,

marking means including graving tools and a tool spacedly provided therein in accordance with the drive for marking said workpiece, .a motor for graduation to be reproduced, means for displacdriving said spindle, a clutch interposed between ing said. templet in accordance with the dissaid motor and said spindle, means for projectplacement of said workpiece, marking means ining a light ray onto said transparent and opaque cluding graving tools and a tool drive vfor marking zones ofthe templet, photlectric means actusaid workpiece, a motor for driving said spindle, ated by said light ray in predetermined positions a clutch interposed between said motor and said of said templet to disengage said clutch, and spindle, means for projecting a light ray onto said means actuated by said tool drive to cause retemplet, photoelectric means actuated by said engagement of said clutch upon completion of the iight ray in predetermined positions of said temworking stroke of thegraving tools. y piet to disengage said clutch, and m'eans actu- 10. In an apparatus for providing graduation ated by said tool drive to causeA reengagement marks on a workpiece, the combination comprisof said clutch upon completion of the working ing means including a workpiece spindle for instroke of the graving tools. termittently displacing a workpiece, a templet Y constituted of an endless strip of flexible material HANS (J OHANN KONRAD) WAGNER. having zones permeable and impermeable to light HANS-JOACHIM SOMMER. 

